This invention relates to apparatus for positioning a block with respect to an axis determined from data obtained by scanning of the block's periphery. More particularly, the invention concerns such a positioner used as a charger for a lathe, where the block takes the form of a log section and the log section is to be mounted in a lathe for rotation about an axis determined to produce maximum veneer production from the log section.
With the supply of timber becoming ever more restricted, and with logs when they are available usually being from second or third growth and of smaller size than the size of old growth logs, it is becoming increasingly important in the making of plywood that logs be cut in such a manner as to produce maximum veneer production. Furthermore, if plywood produced from the veneer is to be competitive with other building materials, the handling and cutting of the logs must be done in an efficient manner, and with automated or semi-automated equipment with minimal use of manpower.
In prior issued patent U.S. Pat. No. 4,802,946, there is disclosed a method of constructing laminated panels, i.e., plywood panels, which utilizes veneer pieces for all layers in the panel of a standard and uniform size. The procedure disclosed in this patent makes for economies through reducing trim loss associated with the production of a panel and reducing the handling of veneer pieces in their clipping, sorting, drying, storing, laying up, etc. The block positioner of the instant invention is well suited for the practicing of the method of this patent, as it makes possible the handling of log sections of relatively small diameters, as typifies second growth, with minimal manpower requirements and in an efficient manner.
Included among the general objects of this invention is the provision of a log positioner, including chuck means for gripping opposite ends of a log section or block, which is displaceable in x and y directions extending laterally of a rotation axis to change the rotation axis of the log held in the positioner.
Another general object is to provide a positioner which includes chuck means for holding the ends of a log section where the ends of a log section are held by means engaging its perimeter. Specifically, a chuck means may comprise a tapered hollow receptacle, which operates when a log end is inserted thereinto to funnel the end to a more-or-less centered position. Such a chuck means may readily handle log sections of varying diameters, with the mere act of gripping the ends of a log section serving roughly to center the log section through this funnelling action.
Another object is to provide, in a log positioner or like device, an orbital chuck, i.e., a chuck which may rotate about an axis which is offset from its center and a chuck wherein this offset is adjustable in x and y directions.
A further object is to provide a log positioner which includes chucks for gripping the ends of a log section or block, and which further includes scanning means for scanning the periphery of a block held, and means for producing adjustments in the chucks after scanning the log periphery with the log subsequently being rotatable to enable additional data to be obtained leading to a more finely tuned adjustment of the chucks.
Another object is to provide a block positioner with means for supplying blocks to the positioner which supports the blocks inwardly from their ends, chucks in the block positioner which engage or grip the ends of blocks by gripping their peripheries, and means for then holding the blocks and transferring them to a lathe which grips the blocks through engaging the ends of the blocks.
Yet another object is to provide in a positioner the combination of a primary and a secondary chuck, where the primary chuck engages the end of a block by engaging its perimeter at the end, the secondary chuck being extensible beyond the primary chuck to grip a log through its end to hold a block prior to its being transferred to a lathe.